Loop and check if integer

Question

I have an exercise:

Write code that asks the user for integers, stops loop when 0 is given. Lastly, adds all the numbers given and prints them.

So far I manage this:

a = None
b = 0
while a != 0:
    a = int(input("Enter a number: "))
    b = b + a
print("The total sum of the numbers are {}".format(b))

However, the code needs to check the input and give a message incase it is not an integer.

Found that out while searching online but for the life of me I cannot combine the two tasks.

while True:
    inp = input("Input integer: ")
    try:
        num = int(inp)
    except ValueError:
        print('was not an integer')
        continue
    else:
        total_sum = total_sum + num
        print(total_sum)
        break

I suspect you need an if somewhere but cannot work it out.

What do you mean by "combine"? The second code would basically replace the first code. What parts of the first code do you feel are missing in the second code? — mkrieger1, Apr 18 '22 at 22:15
In the `else` clause check to see if the value of `num` is zero — meaning it's time to stop the loop by printing the sum and `break` — otherwise just add it to the running total. — martineau, Apr 18 '22 at 22:51

score 1 · Accepted Answer · answered Apr 18 '22 at 22:23

Based on your attempt, you can merge these two tasks like:

a = None 
b = 0 
while a != 0: 
    a = input("Enter a number: ") 
    try: 
        a = int(a) 
    except ValueError: 
        print('was not an integer') 
        continue 
    else: 
        b = b + a  
print("The total sum of the numbers are {}".format(b))

score 1 · Answer 2 · answered Apr 18 '22 at 22:26

If you want to use an If-Statement, you don't need the else: If the number is not 0 it will just start again until it's 0 sometime.

total_sum = 0
while True:
    inp = input("Input integer: ")
    try:
        num = int(inp)
    except ValueError:
        print('was not an integer')
        continue
    total_sum = total_sum + num
    if num == 0:
        print(total_sum)
        break

score 0 · Answer 3 · answered Apr 18 '22 at 22:31

Since input's return is a string one can use isnumeric no see if the given value is a number or not.

If so, one can convert the string to float and check if the given float is integer using, is_integer.

a = None 
b = 0 
while a != 0: 
    a = input("Enter a number: ") 
    if a.isnumeric():
        a = float(a)
        if a.is_integer():
            b += a
        else:
            print("Number is not an integer")
    else:
        print("Given value is not a number")
        
print("The total sum of the numbers are {}".format(b))

Loop and check if integer

3 Answers3